/Engine/Plugins/Experimental/ChaosVehiclesPlugin/Source/ChaosVehicles/Public/ChaosVehicleMovementComponent.h
Set the user input for gear (-1 reverse, 0 neutral, 1+ forward)
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, Category="Game|Components|ChaosVehicleMovement") void SetTargetGear ( int32 GearNum, bool bImmediate )